Dhaka, Nov. 6 -- Dark circles, a dull complexion, shedding hair and brittle nails have found a new suspect on TikTok: low ferritin.

Dubbed "ferritin face", the trend links such changes to low ferritin, the protein that stores iron, Vogue reports.

The hashtag has drawn over 16 million TikTok views, and UK Google searches are up 5,000 percent since October, the fashion magazine says.

Ferritin levels reflect the body's iron reserves, which support oxygen transport, energy production and healthy hair and nails.

Health professionals, however, caution that these visible changes can have many causes, including genetics, hormonal changes, dehydration, stress and poor sleep.

"Ferritin face" is not a recognised medical diagnosis, and people ca...